Extended difunctional end-cap monomers

ABSTRACT

High performance composites can be made from linear or multidimensional oligomer or blends that include unsaturated hydrocarbon crosslinking functionalities linked to a benzenetriyl or pyrimidine radical on the terminal ends of the polymeric backbones of the oligomers. The oligomers are made by condensing benzenetriyl or pyrimidine-based end-cap monomers of the formulas: ##STR1## wherein R 1  =lower alkyl, lower alkoxy, aryl, aryloxy, substituted alkyl, substituted aryl, halogen, or mixtures thereof; 
     j=0, 1, or 2; 
     G=--CH 2  --, --O--, --S--, --SO--, --CO--, --CHR--, --CR 2  --, or --SO 2  --; 
     T=methallyl or allyl; 
     Me=methyl; 
     R=hydrogen, lower alkyl, or phenyl; 
     Ph=phenyl; ##STR2## Q=--NH 2 , --COX, --NO 2 , or --COOH, with suitable polymeric precursors.

This is a division of U.S. Ser. No. 07/868,295, filed Apr. 14, 1992, nowU.S. Pat. No. 5,175,233, which is a division of U.S. Ser. No.07/578,525, filed Jul. 10, 1990, now U.S. Pat. No. 5,112,939 which is adivision of application Ser. No. 06/167,597, filed Mar. 14, 1988, nowU.S. Pat. No. 4,980,481, which is a continuation-in-part of Ser. No.06/816,489, filed Jan. 6, 1986, now U.S. Pat. No. 4,739,030, which is acontinuation-in-part of Ser. No. 06/704,475, filed Feb. 22, 1985, nowabandoned, which is a divisional of Ser. No. 06/505,348, filed Jun. 17,1983, now U.S. Pat. No. 4,536,559.

TECHNICAL FIELD

The present invention pricipally relates to benzenetriyl-based andpyrimidine-based end-cap monomers that provide two crosslinking sitesfor preparing high performance oligomers and blends and allowing thepreparation of solvent-resistant advanced composites.

BACKGROUND OF THE INVENTION

Recently, chemists have sought to synthesize oligomers for highperformance advanced composites suitable for aerospace applications.These composites should exhibit solvent resistance; be tough, impactresistant, and strong; be easy to process; and be thermoplastic.Oligomers and composites that have thermo-oxidative stability and,accordingly, can be used at elevated temperatures are particularlydesirable.

While epoxy-based composites are suitable for many applications, theirbrittle nature and susceptibility to thermal or hydrolytic degradationmake them inadequate for many aerospace applications, especially thoseapplications which require thermally stable, tough composites.Accordingly, research has recently focused on polyimide composites toachieve an acceptable balance between thermal stability, solventresistance, and toughness. Still the maximum temperatures for use of thepolyimide composites, such as PMR-15, are about 600°-625° F., since theyhave glass transition temperatures of about 690° F. PMR-15, however,suffers from brittleness.

There has been a progression of polyimide sulfone compounds synthesizedto provide unique properties or combinations of properties. For example,Kwiatkowski and Brode synthesized maleic-capped linear polyarylimides asdisclosed in U.S. Pat. No. 3,839,287. Holub and Evans synthesizedmaleic- or nadic-capped, imido-substituted polyester compositions asdisclosed in U.S. Pat. No. 3,729,446. We synthesized thermally stablepolysulfone oligomers as disclosed in U.S. Pat. No. 4,476,184 or U.S.Pat. No. 4,536,559, and have continued to make advances withpolyetherimidesulfones, polybenzoxazolesulfones, polybutadienesulfones,and "star" or "star-burst" multidimensional oligomers. We have shownsurprisingly high glass transition temperatures yet reasonableprocessing and desirable physical properties in many of these oligomersand their composites.

Polybenzoxazoles, such as those disclosed in U.S. Pat. No. 4,965,336 (toLubowitz & Sheppard) and U.S. Pat. No. 4,868,270 (to Lubowitz, Sheppard,and Stephenson), may be used at temperatures up to about 750°-775° F.,since these composites have glass transition temperatures of about 840°F. Some aerospace applications need composites which have even higheruse temperatures while maintaining toughness, solvent resistance, easeof processing, formability, strength, and impact resistance.

Multidimensional oligomers, such as disclosed in our copendingapplications U.S. Ser. No. 06/810,817, now abandoned, and 07/000,605,are easier to process than some advanced composite oligomers since theycan be handled at lower temperatures. Upon curing, however, theoligomers crosslink (homopolymerize) through their end caps so that thethermal resistance of the resulting composite is markedly increased withonly a minor loss of stiffness, matrix stress transfer (impactresistance), toughness, elasticity, and other mechanical properties.Glass transition temperatures above 950° F. are achievable.

Commercial polyesters, when combined with well-known diluents, such asstyrene, do not exhibit satisfactory thermal and oxidative resistance tobe useful for aircraft or aerospace applications. Polyarylesters areoften unsatisfactory, also, since the resins often are semicrystallinewhich may makes them insoluble in laminating solvents, intractable infusion, and subject to shrinking or warping during compositefabrication. Those polyarylesters that are soluble in conventionallaminating solvents remain so in composite form, thereby limiting theirusefulness in structural composites. The high concentration of estergroups contributes to resin strength and tenacity, but also makes theresin susceptible to the damaging effects of water absorption. Highmoisture absorption by commercial polyesters can lead to distortion ofthe composite when it is loaded at elevated temperature.

High performance, aerospace, polyester advanced composites, however, canbe prepared using crosslinkable, end capped polyester imide ethersulfone oligomers that have an acceptable combination of solventresistance, toughness, impact resistance, strength, case of processing,formability, and thermal resistance. By including Schiff base(--CH═N--), imidazole, thiazole, or oxazole linkages in the oligomerchain, the linear, advanced composites formed with polyester oligomersof application U.S. Ser. No. 06/726,25, now abandoned can havesemiconductive or conductive properties when appropriately doped.

Conductive and semiconductive plastics have been extensively studied(see, e.g., U.S. Pat. Nos. 4,375,427; 4,338,222; 3,966,987; 4,344,869;and 3,344,870), but these polymers do not possess the blend ofproperties which are essential for aerospace applications. That is, theconductive polymers do not possess the blend of (1) toughness, (2)stiffness, (3) elasticity, (4) ease of processing, (5) impact resistance(and other matrix stress transfer capabilities), (6) retention ofproperties over a broad range of temperatures, and (7) high temperatureresistance that is desirable on aerospace advanced composites. The priorart composites are often too brittle.

Thermally stable multidimensional oligomers having semiconductive orconductive properties when doped with suitable dopants are also knownand are described in our copending applications (including U.S. Ser. No.06/773,381 to Lubowitz, Sheppard and Torre). The linear arms of theoligomers contain conductive linkages, such as Schiff base (--N═CH--)linkages, between aromatic groups. Sulfone and ether linkages areinterspersed in the arms. Each arm is terminated with a mono- ordifunctional end cap (i.e. an end cap having one or two crosslinkingfunctionalities) to allow controlled crosslinking upon heat-induced orchemically-induced curing. Other "semiconductive" oligomers aredescribed in our other copending applications.

Polyamide oligomers and blends are described in U.S. Pat. Nos. 4,935,523and 4,847,333, and polyetherimide oligomers and blends are described inU.S. Pat. No. 4,851,495.

Polyamideimides are generally injection-moldable, amorphous, engineeringthermoplastics which absorb water (swell) when subjected to humidenvironments or immersed in water. Polyamideimides are generallydescribed in the following patents: U.S. Pat. Nos. 3,658,938; 4,628,079;4,599,383; 4,574,144; or 3,988,344. The thermal integrity andsolvent-resistance can be greatly enhanced by capping amideimidebackbones with monomers that present one or two crosslinkingfunctionalities at each end of the oligomer, as described in applicationU.S. Ser. No. 07/092,740, now abandoned.

In all of these cases, the advantages are achieved by use of unsaturatedhydrocarbon radicals at the ends of the polymeric backbones, whichcrosslink by addition polymerization when the oligomers are cured. Theradicals (D) generally are selected from the group consisting of:##STR3## wherein R₁ =lower alkyl, lower alkoxy, aryl, substituted aryl,substituted alkyl (including hydroxyl or halo substituents), aryloxy,halogen, or mixtures thereof;

j=0, 1, or 2;

Me=methyl;

G=--SO₂ --, --CH₂ --, --S--, --O--, --CO--, --SO--, --CHR--, or --CR₂ --(preferably --CH₂ -- or --O--);

E=methallyl or allyl; and

R=hydrogen, lower alkyl, or phenyl.

The radicals can be the residue of an anhydride that is reacted with anamino-terminated polymeric backbone (or be included in the reactionmixture of polymeric precursors used for synthesizing such a backbone)or can be condensed with aminophenol, nitroaniline, aminobenzoic acid,diaminophenol, diaminobenzoic acid or the like to form a mono- ordifunctional end-cap monomer.

SUMMARY OF THE INVENTION

We have found that high performance oligomers useful in aerospaceapplications can be prepared using pyrimidine or phenyl end-cap monomershaving the formulas: ##STR4## R₁ =lower alkyl, lower alkoxy, aryl,aryloxy, substituted alkyl, substituted aryl, halogen, or mixturesthereof;

j=0, 1, or 2;

G=--CH₂ --, --O--, --S--, --SO--, --CO--, --CHR--, --CR₂ --, or --SO₂--;

T=methallyl or allyl;

Me=methyl;

R=hydrogen, lower alkyl, or phenyl;

Ph=phenyl; ##STR5## Q=--NH₂, --COX, --COOH or --NO₂ ; and X=halogen.

These benzenetriyl and pyrimidine-based end-cap monomers can becondensed with suitable reactants to form high performance oligomerssuch as ethers or esters, as will be explained. The oligomers can beprocessed into prepregs and composites the prepregs or composites mayinclude additional coreactants or noncrosslinking, compatible polymers.

BEST MODE CONTEMPLATED FOR CARRYING OUT THE INVENTION

The pyrimidine-based end-cap monomers of the present invention areprepared by condensing an anhydride of the general formula: ##STR6##wherein R₁ =lower alkyl, lower alkoxy, aryl, substituted aryl,substituted alkyl (including hydroxyl or halo substitutents), aryloxy,halogen, or mixtures thereof;

j=0, 1, or 2;

Me=methyl;

G=--SO₂ --, --CH₂ --, --S--, --O--, --CO--, --SO--, --CHR--, or --CR₂ --(preferably --CH₂ -- or --O--);

E=methallyl or allyl; and

R=hydrogen, lower alkyl, or phenyl,

with a pyrimidine of the formula: ##STR7## wherein B=--OH or halogen(preferably, chlorine); and

R₃ =hydrogen, lower alkyl, or aryl (and, preferably, hydrogen)

The products are counterparts of the difunctional imidophenol end-capmonomers described in U.S. Pat. No. 4,739,030, made by condensing theanhydrides with diaminophenol, in the manner described in U.S. Pat. No.4,604,437 with respect to the allyl- or methallyl-substitutedmethylbicyclo[2.2.1]hept-5-ene-2,3-dicarboximides. A phenyl counterpartof the halopyrimidine cap can be made using a halo-substituteddiaminobenzene.

The aromatic character of the pyrimidine ring should providesubstantially the same benefits as the phenyl ring. The thermo-oxidativestability of the resulting composites, however, might be somewhat lessthan that achieved for the phenyl end cap monomers.

The halo-substituted end cap monomers can be used in condensations withhydroxyl groups to form ether linkages. The hydroxyl-substituted end capmonomers can be used in condensations with halo-, nitro-, or acid halidegroups to form ether or ester linkages. For example, thehalo-substituted pyrimidine end cap monomer might be reacted withphloroglycinol to form an ether, "star burst", multidimensionaloligomer. The hydroxyl-substituted pyrimidine end cap might similarly becondensed with a dicarboxylic acid chloride (i.e. dibasic acid chloride)and a dialcohol (i.e. diol, bisphenol, or dihydric phenol) to form alinear polyester oligomer.

The pyrimidine-based oligomers can be used in advanced composite (mixedchemical) blends that comprise a mixture of a crosslinking oligomer fromone chemical family, generally selected from the group consisting of:

imidesulfone;

ether;

ethersulfone;

amide;

imide;

ester;

estersulfone;

etherimide;

amideimide;

oxazole;

oxazole sulfone;

thiazole;

thiazole sulfone;

imidazole; and

imidazole sulfone,

and a noncrosslinking polymer from a different chemical family.Coreactants may be included in the blends, or they may comprise mixturesof three or more oligomers/polymers, as will be explained. Because theoligomer's average formula weight will appreciably increase upon curing,generally the average formula weight of the polymer in the uncured blendwill be greater than that of the oligomer. For example, a linearoligomer may have an average formula weight of about 500-5000 while thecorresponding polymer has an average formula weight of about20,000-40,000. Upon curing, the oligomer and polymer will generally haveaverage formula weights that are closer because of additionpolymerization of the oligomer. Therefore, the problems sometimesencountered with blends having components of widely different averageformula weight are not as pronounced in the advanced compositecomposites of the present invention.

Advanced composite blends allow tailoring of the properties of highperformance composites. They allow averaging of the properties of resins(i.e. oligomers or polymers) from different chemical families to providecomposites that do not have as severe shortcomings as the purecompounds. For example, the rigid nature of heterocycles (oxazole,thiazole, or imidazole) can be reduced by an advanced composite blendcomprising a heterocycle oligomer and an ethersulfone polymer. Theresulting composite will have a use temperature (thermo-oxidativestability) higher than pure ethersulfone and a flexibility greater thanthe pure heterocycle. Accordingly, the resulting composites have ablending or averaging of physical properties, which makes themcandidates for particularly harsh conditions.

Particularly preferred oligomer/polymer combinations include:

amideimide/imide;

amideimide/imidesulfone;

amideimide/heterocycle;

amideimide/heterocycle sulfone;

imide/heterocycle;

imidesulfone/heterocycle;

imide/heterocycle sulfone;

imide/amide;

imidesulfone/amide;

ester/amide;

estersulfone/amide;

ester/imide;

ester/imidesulfone;

estersulfone/imide; or

estersulfone/imidesulfone.

In each case the oligomer can be either component in the mixture.

Linear oligomers have the general formula:

    D.sub.i --A--D.sub.i

wherein

i=1 or 2;

A=a hydrocarbon residue, preferably from one of the families previouslydescribed and having an aromatic, aliphatic, or aromatic and aliphaticbackbone; and

D=an unsaturated hydrocarbon radical that is suitable for crosslinking,and generally includes the residue of a pyrimidine-based end cap thathas previously been described.

The oligomeric component of an advanced composite blend may itself be acoreactive oligomer blend rather than a single oligomeric component.That is, the oligomer may include two precursors that polymerize to formblock copolymers upon curing through mutually reactive end caps on therespective precursors. The resulting composites include a mix ofaddition polymers created by crosslinking chain extension and blockcopolymers formed through a resin interlinking reaction. The linearcoreactive oligomer blends generally include at least one oligomer ofthe general formula:

    D.sub.i --A--D.sub.i

wherein

i=1 or 2;

A=a hydrocarbon backbone; and

D=an unsaturated hydrocarbon residue as previously described, butpreferably one selected from the group consisting of: ##STR8## G=--SO₂--, --S--, --O--, --CO--, or --CH₂ --; and R=hydrogen, lower alkyl, orphenyl

and another oligomer of the general formula:

    Z.sub.i --B--Z.sub.i

wherein

i=1 or 2;

B=a hydrocarbon backbone that is from the same or a different chemicalfamily as A; and

Z=a hydrocarbon residue including a segment selected from the groupconsisting of: ##STR9## X=--O-- or --S--. The backbones (A or B) in thiscircumstance of coreactive oligomer blends, as with the pure componentoligomers, are generally individually selected from the group consistingof:

imidesulfones;

ethersulfones;

amides;

ethers;

esters;

estersulfones;

imides;

etherimides;

amideimides;

oxazoles;

thiazoles;

imidazoles, or

heterocycle (i.e. oxazole, thiazole

imidazole) sulfones;

and generally include only aromatic (typically phenyl) radicals betweenlinkages, although they may have other aromatic, aliphatic, or aromaticand aliphatic radicals. Although this description will primarilydescribe para isomers of these backbones, other isomers (particularlymeta) can be used. The aromatic radicals in the backbones may includenonreactive substituents in some cases.

Linear oligomers of the general formula: D_(i) --A--D_(i), or Z_(i)--B--Z_(i) are preferably prepared by simultaneously condensing suitableend cap monomers with the monomer reactants (i.e. polymeric precursors)that are commonly used to form the desired backbones. For example, animide or an imidesulfone is prepared by reacting an amine end capmonomer with a diamine and a dianhydride in accordance with the methoddescribed in U.S. Pat. No. 4,584,364. Ethersulfones or ethers can beprepared by reacting a halo- or hydroxyl end cap monomer with a suitabledialcohol (i.e. diol, bisphenol, or dihydric phenol) and a dihalogen asdescribed in U.S. Pat. No. 4,414,269 or by other ether condensationreactions.

An amine pyrimidine-based end cap monomer can be prepared by reactingaminophenol with the halo-substituted end cap, or the reaction mixturecan include about 2 moles of the halo-pyrimidine end cap, about 2 molesof aminophenol, about m moles of diamine, and about m+1 molesdianhydride wherein m=a small integer, generally from about 1-5.Alternatively, the hydroxyl-substituted pyrimidine end cap can bereacted with nitroaniline, aminobenzoic acid, or aminobenzoic acidchloride to provide a reactive amine functionality. Again, the reactionmixture might simply include the hydroxyl-substituted pyrimidine endcap, the aminobenzoic acid chloride, the diamine, and the dianhydride,although stepwise reaction is preferred to avoid the side reaction ofthe acid halide and diamine.

The end cap monomers generally are selected from the group previouslydescribed, wherein, for coreactive blends, the radical preferably is:##STR10## wherein i=1 or 2;

G=--SO₂ --, --S--, --O--, --CO--, --CH₂ --, --SO--, --CHR--, or --CR₂--;

R=hydrogen, lower alkyl, or phenyl;

W=--OH, or --X; and

X=halogen.

Similarly, the end cap monomers for the Z_(i) --B--Z_(i) oligomersgenerally are selected from the group consisting of aminophenol,aminobenzoic acid halide, H₂ N--φ--SH, ##STR11## or the like, whereinφ=phenyl and W=--OH, --NH₂, or --COX.

Upon curing, each oligomer in the coreactive oligomer blends additionpolymerizes by crosslinking and forms block copolymers through theMichaels addition reaction between the hydrocarbon unsaturation of oneoligomer and the amine, hydroxyl, or sulfhydryl group of the other. Thereaction of the hydrocarbon unsaturation of one oligomer with the##STR12## functionality of the other follows the mechanism described inU.S. Pat. No. 4,719,283 to form a cyclohexane linkage by bridging acrossthe double bond. With the acetylene (triple) unsaturation, a cyclohexenelinkage would result.

The Michaels addition reaction is illustrated as follows: ##STR13##wherein V=--NH--, --O--, or --S--. For the other end caps, a reverseDiels-Alder decomposition reaction (induced by heating the oligomers)results in the formation of a reactive maleic moiety and the off-gassingof a cyclopentadiene. The methylene bridge decomposes to the maleiccompound at about 625°-670° F. (330°-355° C.) while the --O-- bridgedecomposes at the lower temperature of about 450° F. (230° C.).

The reactive group might also be --CNO instead of the amine, but we donot recommend use of this compound.

All reactions used in the preparation of the oligomers should be carriedout in suitable solvents and under an inert atmosphere. To prepare imideor imidesulfones, then, of the general formula D_(i) --A--D_(i), orZ_(i) --B--Z_(i), the respective amine end cap preferably is mixed witha diamine and a dianhydride. To prepare ethers or ethersulfones, therespective hydroxy end cap is mixed with suitable dialcohols (i.e.,diols) and dihalogens or dinitro compounds. To prepare amides, therespective amide or acid halide end cap is mixed with suitabledicarboxylic acid halides and diamines. To prepare esters orestersulfones, the respective hydroxy or acid halide end cap is mixedwith suitable dialcohols and dicarboxylic acid halides.

To prepare etherimides, the halo-substituted pyrimidine cab be used orrespective amine end caps are reacted with: ##STR14## wherein Y=nitro-or halo- (i.e. nitrophthalic anhydride or halophthalic anhydride) toform an imide while leaving an active nitro- or halo-functionality. Thisintermediate is then mixed with suitable nitro/anhydrides and compoundsof the formula: H₂ N--R--XH, as suggested in U.S. Pat. Nos. 3,847,869,4,107,147 and 4,851,495.

To prepare amideimides, the method of U.S. patent application Ser. No.07/092,740, now abandoned is used, which comprises condensingsimulteneously an amine or acid halide end cap with suitabledicarboxylic acid halides (i.e. diacid halide or dibasic acid halide)and diamines, wherein either or both of the diamines or diacid halideinclude intermediate imide linkages. Alternatively, the amideimides canbe prepared by condensing the respective amine end cap with suitabledianhydrides and diamines, wherein either or both of the dianhydrides ordiamines include amide linkages.

Heterocycle or heterocycle sulfone oligomers (i.e. oxazole, thiazoles,or imidazoles) are prepared by condensing acid halide end caps withfour-functional compounds, like diaminodihydroxybenzene, anddicarboxylic acid halides (or the acids).

Pyrimidine-based acid halide end cap monomers can be prepared bycondensing nitrobenzoic acid halide with the hydroxyl-substitutedmonomer to form an extended ether pyrimidine monomer having an activeacid halide functionality.

The synthesis of these oligomers and the representative classes ofreactants will now be presented in greater detail to illustrate thescope of the invention and to describe the nature of the preferredreactants.

Amideimides are characterized by backbones of two general types, namely:##STR15## wherein R₃ =an aromatic, aliphatic, or alicyclic radical, andpreferably a phenoxyphenyl sulfone; and

R₂ =a trivalent organic radical, and preferably phenyl.

Accordingly, linear polyamideimides include oligomers of the generalformula: ##STR16## wherein Y=an end cap residue that includes a D or Zradical;

R₂ =a trivalent organic radical, and preferably phenyl;

R₃ =an aromatic, aliphatic, or alicyclic radical, and preferably aphenoxyphenyl sulfone.

R₄ =a divalent organic radical;

m=a small integer, usually from 0-5, but generally sufficiently large toimpart thermoplastic properties in the oligomer;

φ=phenyl; and

i=1 or 2.

The amideimides are generally made by condensing suitable end capmonomers, diacid halides, diamines, and dianhydrides. The diacid halidescan be prepared by condensing 2 moles of an acid halide anhydride of theformula: ##STR17## with a diamine of the formula: H₂ N--R₃ --NH₂. Thediamine, in this case, can be selected from the group consisting of:##STR18## q=--SO₂ --, --CO--, --S--, or --(CF₃)₂ C--; Me=methyl;

m=a small integer; and

D=--CO--, --SO₂ --, --(CF₃)₂ C-- or mixtures thereof.

Other diamines that may be used, but that are not preferred, includethose described in U.S. Pat. Nos. 4,504,632; 4,058,505; 4,576,857;4,251,417; and 4,215,418. The aryl or polyaryl "sulfone" diaminespreviously described are preferred, since these diamines are soluble inconventional synthetic solvents and provide high thermal stability tothe resulting oligomers and composites.

Diamines may include "Schiff base" conductive linkages (particularly--N═CH--), analogous to diacid halides which will be described.

Particularly preferred ethersulfone (i.e. phenoxyphenyl sulfone)diamines are those in which R₁ is ##STR19## so that the phenoxyphenylsulfone diamines include: ##STR20##

The molecular weights of these diamines varies from about 500 to about2000. Using lower molecular weight diamines seems to enhance themechanical properties of the difunctional polyamideimide oligomers, eachof which has alternating ether "sulfone" segments in the backbone.

Phenoxyphenyl sulfone diamines of this general nature can be prepared byreacting two moles of aminophenol with (n+1) moles of an aryl radicalhaving terminal, reactive halo- functional groups (dihalogens), such as4,4'-dichlorodiphenylsulfone, and a suitable bisphenol (i.e., dialcohol,dihydric phenol, or diol). The bisphenol is preferably selected from thegroup consisting of:

2,2-bis-(4-hydroxyphenyl)-propane (i.e., bisphenol-A);

bis-(2-hydroxyphenyl)-methane;

bis-(4-hydroxyphenyl)-methane;

1,1-bis-(4-hydroxyphenyl)-ethane;

1,2-bis-(4-hydroxyphenyl)-ethane;

1,1-bis-(3-chloro-4-hydroxyphenyl)-ethane;

1,1-bis-(3,5-dimethyl-4-hydroxyphenyl)-ethane;

2,2-bis-(3-phenyl-4-hydroxyphenyl)-propane;

2,2-bis-(4-hydroxynaphthyl)-propane

2,2-bis-(4-hydroxyphenyl)-pentane;

2,2-bis-(4-hydroxyphenyl)-hexane;

bis-(4-hydroxyphenyl)-phenylmethane;

bis-(4-hydroxyphenyl)-cyclohexylmethane;

1,2-bis-(4-hydroxyphenyl)-1,2-bis-(phenyl)-ethane;

2,2-bis-(4-hydroxyphenyl)-1-phenylpropane;

bis-(3-nitro-4-hydrophenyl)-methane;

bis-(4-hydroxy-2,6-dimethyl-3-methoxyphenyl)-methane;

2,2-bis-(3,5-dichloro-4-hydroxyphenyl)-propane;

2,2-bis-(3-bromo-4-hydroxyphenyl)-propane;

or mixtures thereof, as disclosed in U.S. Pat. No. 3,262,914. Bisphenolshaving aromatic character (i.e., absence of aliphatic segments), such asbisphenol-A, are preferred.

The dihalogens in this circumstance preferably are selected from thegroup consisting of: ##STR21## wherein X=halogen, preferably chlorine;and q=--S--, --SO₂ --, --CO--, --(CH₃)₂ C--, and --(CF₃)₂ C--, andpreferably either --SO₂ --or --CO--.

The condensation reaction creates ether diamines that ordinarily includeintermediate "sulfone" linkages. The condensation generally occursthrough a phenate mechanism in the presence of K₂ CO₃ or another base ina DMSO/toluene solvent. The grain size of the K₂ CO₃ (s) should fallwithin the 100-250 ANSI mesh range.

Additional methods for preparing phenoxyphenylsulfones of this generaltype are disclosed in U.S. Pat. Nos. 3,839,287 and 3,988,374.

The diacid halide or dicarboxylic acid (i.e. dibasic acid) may includean aromatic chain segment selected from the group consisting of:

(a) phenyl; (b) naphthyl; (c) biphenyl;

(d) a polyaryl "sulfone" divalent radical of the general formula:##STR22## wherein D=--S--, --O--, --CO--, --SO₂ --, --(CH₃)₂ C--,--(CF₃)₂ C--, or mixtures thereof throughout the chain; or

(e) a divalent radical having conductive linkages, illustrated by Schiffbase compounds selected from the group consisting of: ##STR23## whereinR is selected from the group consisting of: phenyl; biphenyl; naphthyl;or a divalent radical of the general formula: ##STR24## wherein W=--SO₂-- or --CH₂ --; and q=0-4; or

(f) a divalent radical of the general formula: ##STR25## wherein R¹ =aC₂ to C₁₂ divalent aliphatic alicyclic, or aromatic radical, and,preferably, phenyl (as described in U.S. Pat. No. 4,556,697).

Thiazole, oxazole, or imidazole linkages, especially between arylgroups, may also be used as the conductive linkages to form theconductive or semiconductive oligomers.

The preferred diacid halides include: ##STR26##

Schiff base dicarboxylic acids and diacid halides can be prepared by thecondensation of aldehydes and aminobenzoic acid (or other amine acids)in the general reaction scheme: ##STR27## or similar syntheses.

Other diacid halides that can be used, but that are not preferred, aredisclosed in U.S. Pat. No. 4,504,632, and include:

adipylchloride,

malonyl chloride,

succinyl chloride,

glutaryl chloride,

pimelic acid dichloride,

suberic acid dichloride,

azelaic acid dichloride,

sebacic acid dichloride,

dodecandioic acid dichloride,

phthaloyl chloride,

isophthaloyl chloride,

terephthaloyl chloride,

1,4-naphthalene dicarboxylic acid dichloride, and

4,4'-diphenylether dicarboxylic acid dichloride.

Polyaryl or aryl diacid halides are preferred to achieve the highestthermal stabilities in the resulting oligomers and composites insofar asaliphatic bonds are not as thermally stable as aromatic bonds.Particularly preferred compounds include intermediate electronegative(i.e., "sulfone") linkages to improve toughness of the resultingoligomers.

The corresponding amideimide of the formula: ##STR28## can be preparedif the acid anhydride: ##STR29## is used instead of the acid halideanhydride. The resulting intermediate products are dicarboxylic acidsrather than dianhydrides. These dicarboxylic acids (or their diacidhalides) can be used with the diamines previously described.

Dianhydrides useful for the synthesis of amideimides include:

(a) pyromellitic dianhydride,

(b) benzophenonetetracarboxylic dianhydride (BTDA), and

(c) 5-(2,5-diketotetrahydrofuryl)-3-methylcyclohexene-1,2-dicarboxylicanhydride (MCTC),

but may be any aromatic or aliphatic dianhydride, such as thosedisclosed in U.S. Pat. Nos. 3,933,862; 4,504,632; 4,577,034; 4,197,397;4,251,417; 4,251,418; or 4,251,420. Mixtures of dianhydrides might beused. Lower molecular weight dianhydrides are preferred, and MCTC orother aliphatic dianhydrides are the most preferred for the lower curingpolyamideimides having caps with two crosslinking functionalities.

Of course, the dianhydrides also include those intermediates resultingfrom the condensation of the acid halide anhydride with any of thediamines previously described. Similarly, the dicarboxylic acids anddiacid halides include those intermediates prepared by the condensationof the acid anhydride with any of the diamines previously described. Thecorresponding dicarboxylic acid is converted to the diacid halide (i.e.chloride) in the presence of SOCl₂.

The amideimides of the present invention can be synthesized by severalschemes, as previously described. To obtain repeating units of thegeneral formula: ##STR30## an acid halide anhydride particularly##STR31## can be mixed with a diamine and with an amine end cap in theratio of n:n:2 wherein n=an integer greater than or equal to 1. In thisreaction, the acid halide anhydride will react with the diamine to forman intermediate dianhydride which will condense with the diamine andamine end cap. The reaction may be carried out in two distinct stagesunder which the dianhydride is first prepared by mixing substantiallystoichiometric amounts (or excess diamine) of the acid halide anhydrideand diamine followed by the addition of a mixture of more diamine andthe end cap. Of course, the diamine used to form the dianhydride maydiffer from that used in the second stage of the reaction, or it may bea mixture of diamines from the outset.

The related amideimide having repeating units of the general formula:##STR32## can be synthesized by reacting the acid anhydride with thediamine to form intermediate dicarboxylic acids, which can then reactwith more diamine or an amine end cap to complete the oligomer. Again,the reaction can be separated into steps.

The amideimide oligomers (as with all oligomers) appear to possessgreater solvent resistance if the condensation of thedianhydride/dicarboxylic acid with the diamine and end cap is donesimultaneously rather than sequentially.

While use of an amine end cap has been described above, correspondingoligomers can be formed by using an acid halide end cap, if the diamineis provided in excess. In this case the reaction mixture generallycomprises the acid halide anhydride or the acid anhydride, the end cap,and the diamine and the synthesis is completed generally in one step.

All reactions should be conducted under an inert atmosphere and atelevated temperatures, if the reaction rate needs to be increased. Thereaction mixture should be well stirred throughout the synthesis.Chilling the reaction mixture can slow the reaction rate and can assistin controlling the oligomeric product.

As suggested in U.S. Pat. No. 4,599,383, the diamine may be in the formof its derivative OCN--R--NCO, if desired.

The amideimides described in U.S. Pat. Nos. 4,599,383; 3,988,374;4,628,079; 3,658,938; and 4,574,144 can all be capped with thecrosslinking monomers to convert the polymers to oligomers that aresuitable for forming advanced composite blends.

Polyetherimides and polysulfoneimides are capped to form oligomers thatare suitable for use in the coreactive oligomer blends. Preferredcompounds have the general formula: ##STR33## wherein X=--O--; ##STR34##n=1 or 2; Z₁ =D or Z, as previously defined;

R=a trivalent C.sub.(6-13) aromatic organic radical;

R₁ =any of lower alkyl, lower alkoxy, aryl, substituted alkyl, orsubstituted aryl (including hydroxyl or halo substituents);

R₁ =a divalent C.sub.(6-30) aromatic organic radical; ##STR35##φ=phenyl.

The polyetherimide oligomers can be prepared by several reactionschemes. One such method comprises the simultaneous condensation of:##STR36## in the ratio of I:II:III:IV=1:1:m:m+1, wherein m is an integergreater than or equal to one. The product has the general formulapreviously described, wherein Y₁ =halo- or nitro-. The reaction occursin a suitable solvent under an inert atmosphere. If necessary, thereaction mixture can be heated to facilitate the reaction. The reactionconditions are generally comparable to those described in U.S. Pat. Nos.3,847,869 and 4,107,147.

Compounds of formula (I) can be prepared by condensing thehydroxyl-substituted pyrimidine end cap monomers with nitrophthalicanhydride. Compounds of formula (II) can be prepared by condensing thehydroxyl-substituted pyrimidine end cap monomers with aminobenzoic acidhalide or nitroaniline or by condensing the halo-substituted pyrimidineend cap with aminophenol, each case followed by condensation of theresulting amine with nitro- or halophthalic anhydride.

Alternatively, the polyetherimides can be prepared by reacting apolyetherimide polymer made by the self-condensation of a phthalimidesalt of the formula: ##STR37## with crosslinking end cap moieties of theformulae: ##STR38## wherein X, A₁, A₂, R, and Y₁ are as previouslydefined,

R=a divalent C.sub.(6-30) aromatic organic radical, and

M=an alkali metal ion or ammonium salt or hydrogen.

The self-condensation proceeds as described in U.S. Pat. No. 4,297,474in a dipolar aprotic solvent. The end cap moieties can be introducedduring the self-condensation to quench the polymerization, or they mightbe added following completion of the polymerization and recovery of thepolyetherimide polymer from methanol. Improved solvent resistance on thecured composites is best achieved, however, by the quenching sequencerather than by the capping sequence which follows polymerization.

Yet another preferred method for synthesizing the polyetherimides of thepresent invention involves the simultaneous condensation of about 2 m+2moles of nitrophthalic anhydride with about m+1 moles of diamine, aboutm moles of dialcohol (i.e., bisphenol, diol, or dihydric phenol), and 2moles of A₁ --OH in a suitable solvent under an inert atmosphere. Here,the dialcohol may actually be in the form of a phenate.

In this reaction, the diamines (which preferably have aromaticethersulfone backbones) react with the anhydride to form intermediatesof the following nature in the backbone: ##STR39## wherein R₂ =a residueof the diamine. Similarly, the dialcohol reacts with thenitro-functionality to form an ether linkage of the general formula:##STR40## wherein R₃ =a residue of the dialcohol. The A₁ --OH end capsquench the polymerization. The resulting polyetherimides have thegeneral formula: ##STR41##

Another preferred synthesis comprises the simultaneous condensation ofabout 2 m+2 moles of nitrophthalic anhydride with about m+1 moles ofdialcohol, m moles of diamine, and 2 moles A₂ --NH₂ in a suitablesolvent under an inert atmosphere. Again, the dialcohol may be in thephenate form. The resulting oligomer has a general formula: ##STR42##

In any of the syntheses, the dialcohol can be replaced by a comparabledisulfhydryl of the formula: HS--R₂ --SH. Mixtures of dialcohols, ordisulfhydryls, or dialcohols and disulfhydryls can be used.

Although the bisphenols previously described can be used, foretherimides, the dialcohol is generally a polyaryl compound andpreferably is selected from the group consisting of:

HO--Ar--OH;

HO--Ar--L--Ar'--L--Ar--OH;

HO--Ar'--L--Ar--L--Ar'--OH;

wherein

L=--CH₂ --, --(CH₃)₂ C--, --(CF₃)₂ C--, --O--, --S--, --SO₂ -- or--CO--; ##STR43## T and T₁ =lower alkyl, lower alkoxy, aryl, aryloxy,substituted alkyl, substituted aryl, halogen, or mixtures thereof;

q=0-4;

k=0-3; and

j=0, 1, or 2.

The dialcohols also include hydroquinone; bisphenol-A; p,p'-biphenol;4,4'-dihydroxydiphenylsulfide; 4,4'-dihydroxydiphenylether;4,4'-dihydroxydiphenylisopropane;4,4'-dihydroxydiphenylhexafluoropropane; a dialcohol having a Schiffbase segment, the radical being selected from the group consisting of:##STR44## wherein R is selected from the group consisting of: phenyl;

biphenyl;

naphthyl; pr

a radical of the general formula: ##STR45## wherein W=--CH₂ -- or --SO₂--; or a dialcohol selected from the group: ##STR46## wherein L is aspreviously defined;

Me=methyl;

m=an integer, generally less than 5, and preferably 0 or 1; and

D=any of --CO--, --SO₂ --, or --(CF₃)₂ C--.

While bisphenol-A is preferred in the etherimide synthesis (because ofcost and availability), the other dialcohols can be used to add rigidityto the oligomer without significantly increasing the average formulaweight, and, therefore, can increase the solvent resistance. Random orblock copolymers are possible.

Furthermore, the dialcohols may also be selected from the thosedescribed in U.S. Pat. Nos. 4,584,364; 3,262,914; or 4,611,048. Thehydroxy-terminated etherimides of U.S. Pat. No. 4,611,048 can be reactedwith A₂ --NO₂ to provide crosslinking etherimides of the presentinvention. Compounds of the formula A₂ --NO₂ can be prepared by reactingthe halo-substituted pyrimidine end cap monomers with nitrophenol.

Dialcohols of this nature are commercially available. Some may be easilysynthesized by reacting halide intermediates with bis-phenates, such asby the reaction of 4,4'-dichlorodiphenylsulfone with bis(disodiumbiphenolate).

The oligomers can be synthesized in a homogeneous reaction schemewherein all the reactants are mixed at one time (and this scheme ispreferred), or in a stepwise reaction. The diamine and dialcohols can bemixed, for example, followed by addition of the nitrophthalic anhydrideto initiate the polymerization and thereafter the end caps to quench it.Those skilled in the art will recognize the different methods that mightbe used. To the extent possible, undesirable competitive reactionsshould be minimized by controlling the reaction steps (i.e., addition ofreactants) and the reaction conditions.

Suitable diamines include those diamines described with reference to theamideimide synthesis.

Polysulfoneimide oligomers corresponding to the etherimides can beprepared by reacting about m+1 moles of a dianhydride with about m molesof a diamine and about 2 moles of an amine end cap (A₂ --NH₂). Theresulting oligomer has the general formula: ##STR47## wherein R and R'are divalent aromatic organic radicals having from 2-20 carbon atoms. Rand R' may include halogenated aromatic C.sub.(6-20) hydrocarbonderivatives; alkylene radicals and cycloalkylene radicals having from2-20 carbon atoms; C.sub.(2-8) alkylene terminatedpolydiorganosiloxanes; and radicals of the formula: ##STR48## whereinq=--C_(y) H_(2y) --, --CO--, --SO₂ --, --O--, or --S--; and

y=1 to 5.

Comparable polymers, usable in blends of the sulfoneimides, aredescribed in U.S. Pat. No. 4,107,147. Aromatic dithiodianhydrides aredescribed in U.S. Pat. No. 3,933,862.

Heterocycle or heterocycle sulfone oligomers can be prepared by thecondensation of:

(a) 2 moles of a hydroxyl end-cap monomer;

(b) n moles of a four-functional compound, and

(c) (n+1) moles of a suitable dicarboxylic acid halide,

or by the condensation of:

(a) 2 moles of an acid halide end-cap monomer;

(b) (n+1) moles of a four-functional compound; and

(c) n moles of a dicarboxylic acid halide.

Suitable diacid halides include those compounds described with thereference to the amideimide systheses.

The four-functional compound has the general formula: ##STR49## whereinR is an hydrocarbon radical (preferably, an aromatic radical, if thehighest thermal stability is sought); Y=--OH, --NH₂, or --SH; and theamine functionalities (--NH₂) are not substituted on the same carbonatom as the Y substituents. The four-functional compound generally isselected from the group consisting of: dihydoxybenzidine,dimercaptobenzidine, dihydroxydiaminobenzene, dimercaptodiaminobenzene,diaminobenzidine, or a compound having the general formula: ##STR50##wherein M=--CO--, --SO₂ --, --(CF₃)₂ C--, --S--, or --O--; and

Y=--OH, --SH, or --NH₂.

Isomers of the four-functional compound may also be used so long as theisomers include two pairs of an amine and a "Y" functionality onadjacent carbons on an aromatic radical. The resulting oligomers includeoxazole, thiazole, or imidazole linkages.

Polyimide oligomers can be prepared using 2 moles of an amine end cap(e.g., A₂ --NH₂) with n moles of diamine and (n+1) moles of dianhydride.

Preferred diamines for the polyimide condensation include ethersulfonediamines of the general formula: ##STR51## wherein R and R' are aromaticradicals, at least one of R and R' being a diaryl radical wherein thearyl rings are joined by a "sulfone" (i.e. electronegative) linkage, andq is an integer from 0 to 27 inclusive. Preferably R is selected fromthe group consisting of: ##STR52## wherein L=--SO₂ --, --(CF₃)₂ C--, or--S--. R' is preferably selected from the group consisting of: ##STR53##wherein M=--SO₂ --, --S--, --O--, --(CH₃)₂ C--, or --(CF₃)₂ C--.

Preferred diamines are those in which R is ##STR54## Accordingly, thediamines generally contain at least one phenoxyphenylsulfone group, suchas: ##STR55## These diamines have alternating ether and "sulfone"linkages, wherein "sulfone" designates an electronegative linkage(--M--) as previously defined.

The dianhydride may be is5-(2,5-diketotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylicanhydride (MCTC), an unsaturated, aliphatic dianhydride.

The diamines and dianhydrides react to form repeating imide linkagesalong the generally linear backbone of the oligomers. Preferredproperties in the oligomer are obtained when the backbone isperiodically disrupted by the inclusion of an aliphatic moiety,especially an MCTC residue.

Diamines which include phenoxyphenylsulfone moieties are preferred,since these diamines provide the blend of physical properties in theoligomers which are desired. Impact resistance and toughness is affordedwith the electronegative "sulfone" linkages which act as joints orswivels between the aryl groups. The aliphatic residues, such as thosefrom MCTC, provide lower melt temperatures, and allow the use of lowertemperature end caps, such as oxynadic and dimethyl oxynadic (DONA) endcaps. The resulting oligomers cure at lower temperatures than othersolvent-resistant oligomers, have the desirable features of polyimides,and have better solvent-resistance than conventional polyimides, such asthose described in U.S. Pat. Nos. 3,998,786 or 3,897,395 (D'Alelio).

These polyimide oligomers may be used to form prepregs by theconventional method of impregnating a suitable fabric with a mixture ofthe oligomer and a solvent. Suitable coreactants, such asp-phenylenediamine, benzidine, and 4,4'-methylenedianiline, may be addedto the solvent when preparing prepregs.

The most preferred linear polyimides are prepared with dianhydridesselected from para- and meta- dianhydrides of the general formula:##STR56## wherein M=--SO₂ -- or --CO--, reacted with ##STR57##

Solvent resistant, thermoplastic aromatic poly(imidesulfone) oligomersare also described in U.S. Pat. Nos. 4,398,021 and 4,489,027.Melt-fusible polyimides made by the condensation of dianhydrides anddiamines are described in U.S. Pat. No. 4,485,140.

Polyamides are prepared by condensing dicarboxylic acid halides withdiamines and acid halide or amine end caps. There polyamides aregenerally formed from the diacid halides and diamines that havepreviously been described.

Polyesters or polyestersulfones are prepared by condensing the diacidhalides and dialcohols (i.e., bisphenols, dihydric phenols, or diols)previously described. Polyethers or ethersulfones are prepared bycondensing dinitro compounds or dihalogens and dialcohols or by otherconventional syntheses wherein suitable end-cap monomers are added toquench the synthesis and to provide one or more coreactivefunctionalities at each end of the oligomers.

The dihalogen is generally a compound selected from those describedpreviously with respect to the synthesis of diamines. Dinitro compoundsare generally prepared by reacting nitrophthalic anhydride with thediamines. Of course, dihalogens can be prepared in the same way byreplacing the nitrophthalic anhydride with halophthalic anhydride.Nitroaniline, nitrobenzoic acid, or nitrophenol may also be condensedwith dianhydrides, dicarboxylic acid halides, diamines, dialcohols, ordihalogens to prepare other dinitro compounds that include amide, imide,ether, or ester linkages between the terminal phenyl radicals and theprecursor backbones. The synthesis of the dinitro compounds ordihalogens can occur prior to mixing the other reactants with thesecompounds or the steps can be combined in suitable circumstances todirectly react all the precursors into the oligomers. For example, apolyether oligomer can be prepared by simultaneously condensing amixture of a hydroxyl end cap monomer, nitrophthalic anhydride,phenylene diamine, and HO--φ--O--φ--O--φ--O--φ--OH, wherein φ=phenyl.

While other common resin backbones may be capped in a correspondingmanner and used in advanced composite blends of the present invention,the linear backbones described above are the most directly suited foraerospace applications. Although the concept of advanced compositeblends is probably best suited to linear morphology, however, theadvanced composite blends of the present invention also includemultidimensional oligomers and polymers. Linear morphology is preferredbecause the resulting composites have mixtures of polymers of relativelylarge and roughly equivalent average formula weight. The individualpolymers are similar in structure. We have found it difficult in manycircumstances to process multidimensional oligomers that haveappreciable average formula weights, so the properties of compositesmade from multidimensional advanced composite blends might sufferbecause of diversity of formula weights. Furthermore, the additionpolymerization reaction for multidimensional oligomers results information of a complex, 3-dimensional network of crosslinked oligomersthat is difficult or impossible to match with the multidimensionalpolymers, because these polymers simply have extended chains or shortchains. That is, upon curing, the multidimensional oligomers crosslinkto chemically interconnect the arms or chains through the end caps,thereby forming a network of interconnected hubs with intermediateconnecting chains. The connecting chains have moderate formula weight.Although the cured oligomer can have appreciable formula weight. Incontrast, the polymer (which does not crosslink) simply has a hub witharms of moderate formula weight. While for linear morphology thedisadvantages of blended composites that have a wide diversity ofaverage formula weight polymers as constituents can be overcome bycuring relatively low formula weight oligomers into relatively highaverage formula weight cured polymers that are roughly equivalent to thepolymer constituents, the polymers in the multidimensional morphologyare likely to have average formula weights lower than the oligomericcomponent. Therefore, we believe that the best results for the presentinvention may be achieved with systems having linear morphology.

Although we have yet to verify our theory experimentally, it may bepossible and desirable to synthesize the polymeric component of themultidimensional advanced composite blend when curing the oligomer, and,in the way, forming relatively comparable oligomeric and polymericnetworks. To achieve this effect, we would mix, for example, amultidimensional oligomer with comparable polymeric precursors, such astriamines and tricarboxylic (i.e. tribasic) acid halides. Upon curing,the precursors would condense to form amide linkages to form bridgesbetween hubs in a manner comparable to the oligomeric connecting chains.

A multidimensional oligomer includes an aromatic hub and three or moreradiating chains or arms, each chain terminating with a crosslinking endcap segment. Each chain includes the resin linkages previouslydescribed. Each chain is substantially the same. For example, amultidimensional ether can be prepared by the simultaneous condensationof phloroglucinol with a dihalogen and an imidophenol end cap monomer.

In multidimensional oligomers the higher density of crosslinkingfunctionalities in a multidimensional array provides increasedthermo-oxidative stability to the cured composites. Usually the hub willhave three radiating chains to form a "Y" pattern. In some cases, fourchains may be used. Including more chains leads to steric hindrance asthe hub is too small to accommodate the radiating chains. Atrisubstituted phenyl hub is highly preferred with the chains beingsymmetrically placed about the hub. Biphenyl, naphthyl, azaline (e.g.,melamine), or other aromatic moieties may also be used as the hubradical.

Details of the several preferred multidimensional oligomers will now bedescribed in a manner similar to that used for the linear oligomers.

Multidimensional polyamideimide oligomers include oligomers of thegeneral formula: ##STR58## wherein Y, R₂, R₃, R₄, and m are aspreviously defined with respect to the linear amideimides, Ar=an organicradical of valency w; φ=phenyl, and w=3 or 4. Preferably, Ar is anaromatic radical (generally phenyl) generally selected from phenyl,naphthyl, biphenyl, azalinyl (such as melamine), or triazine derivativesof the general formula: ##STR59## wherein R₅ =a divalent hydrocarbonresidue containing 1-12 carbon atoms, as described in U.S. Pat. No.4,574,154.

The hub may also be a residue of an etheranhydride of the formula:##STR60## or an etheramine of the formula: ##STR61##

The best results are likely to occur when the arm length of theoligomers is as short as possible (to allow ease of processing) and theoligomer has six crosslinking sites (to allow the highest density ofcrosslinking). The most preferred hub includes the phenyl radical, sincethese compounds are relatively inexpensive, are more readily obtained,and provide oligomers with high thermal stability.

The chains of the oligomers include crosslinking end caps which improvethe solvent-resistance of the cured composites. These end caps may bethermally or chemically activated during the curing step to provide astrongly crosslinked, complex, multidimensional array of interconnectedoligomers.

The multidimensional oligomers may be formed by the attachment of armsto the hub followed by chain extension and chain termination. Forexample, trihydroxybenzene may be mixed with p-aminophenol and4,4'-dibromodiphenylsulfone and reacted under an inert atmosphere at anelevated temperature to achieve an amino-terminated "star" of thegeneral formula: ##STR62## that can be reacted with suitable diacidhalides, diamines, and end caps to yield a polyamideimide oligomer.

The etheranhydride hub can be synthesized by reacting nitrophthalicanhydride or halophthalic anhydride with ##STR63## in a suitable solventunder an inert atmosphere, as described generally in our copendingapplication, U.S. Ser. No. 016,703 and in U.S. Pat. No. 3,933,862(thio-analogs).

The oligomers, of course, might be made by reacting nitrophthalicanhydride with an amine end cap followed by the condensation with thehydroxy hub or in similar reaction schemes that will be understood bythose of ordinary skill.

The simplest multidimensional pyrimidine-based oligomers can be preparedby reacting the halo-substituted end cap with phloroglucinol, thehydroxyl-substituted end cap monomer with trichlorobenzene, or thehydroxyl-substituted end cap monomer with cyuranic acid chloride.

The oligomers can be synthesized in a homogeneous reaction schemewherein all the reactants are mixed at one time, or in a stepwisereaction scheme wherein the radiating chains are affixed to the hub andthe product of the first reaction is subsequently reacted with the endcap groups. Of course, the hub may be reacted with end-capped arms thatinclude one reactive, terminal functionality for linking the arm to thehub. Homogeneous reaction is preferred, resulting undoubtedly in amixture of oligomers because of the complexity of the reactions. Theproducts of the processes (even without distillation or isolation ofindividual species) are preferred oligomer mixtures which can be usedwithout further separation to form the desired advanced composites.

Linear or multidimensional oligomers can be synthesized from a mixtureof four or more reactants so that extended chains may be formed. Addingcomponents, however, adds to the complexity of the reaction and of itscontrol. Undesirable competitive reactions may result or complexmixtures of macromolecules having widely different properties may beformed, because the chain extenders and chain terminators are mixed, andcompete with one another.

Multidimensional etherimides can be made by reacting the etheranhydridehub with compounds of the formulae II, III, and IV previously described.

Multidimensional amides are prepared by condensing a nitro, amine, oracid halide hub with suitable diamines, dicarboxylic acid halides, andamine or acid halide end cap monomers to form oligomers of the generalformulae: ##STR64## wherein Ar, w, and A₂ are as previously defined, P=aresidue of a diamine, and Q=a residue a dicarboxylic acid halide.

Multidimensional imides can be made using the amine, etheranhydride, oretheramine hubs with suitable diamines, dianhydrides, and amine oranhydride end caps, as will be understood by those of ordinary skill.

Multidimensional polyesters can be made using hydroxy or carboxylic acidhubs (particularly cyuranic acid) with suitable diols and diacidhalides. Carboxylic acid hubs include those compounds described in U.S.Pat. No. 4,617,390 and compounds prepared by reacting polyols, such asphloroglucinol, with nitrobenzoic acid or nitrophthalic acid to formether linkages and active, terminal carboxylic acid funtionalities. Thenitrobenzoic acid products would have three active sites while thenitrophthalic acid products would have six; each having the respectiveformula: ##STR65## wherein φ=phenyl. Of course other nitro/acids can beused.

Hubs can also be formed by reacting the corresponding halo-hub (such atribromobenzene) with aminophenol to form triamine compounds representedby the formula: ##STR66## which can then be reacted with an acidanhydride to form a polycarboxylic acid of the formula: ##STR67##wherein φ=phenyl; the hub being characterized by an intermediate etherand imide linkage connecting aromatic groups. Thio-analogs are alsocontemplated, in accordance with U.S. Pat. No. 3,933,862.

The hub may also be a polyol such as those described in U.S. Pat. No.4,709,008 to tris(hydroxyphenyl)alkanes of the general formula:##STR68## wherein R=hydrogen or methyl and can be the same or different.The polyols are made by reacting, for example, 4-hydroxybenzaldehyde or4-hydroxyacetophenone with an excess of phenol under acid conditions (asdisclosed in U.S. Pat. Nos. 4,709,008; 3,579,542; and 4,394,469).

The polyols may also be reacted with nitrophthalic anhydride,nitroaniline, nitrophenol, or nitrobenzoic acids to form other compoundssuitable as hubs as will be understood by those of ordinary skill.

Phenoxyphenyl sulfone arms radiating from a hub with a terminal amine,carboxylic acid, or hydroxyl group are also precursors for makingmultidimensional polyester oligomers of the present invention.

The best results are likely to occur when the hub is phloroglucinol orcyuranic acid. In either case a suitable end-cap monomer (hydroxyl,halo, or acid halide) can be reacted with the hub to form "short-armed,"multidimensional oligomers having three or six crosslinking sites. Thesecompounds are the simplest multidimensional oligomers and are relativelyinexpensive to synthesize.

Multidimensional amides, amide imides, heterocycles, and heterocyclesulfones can be prepared using these carboxylic acid hubs, as will beunderstood by those of ordinary skill in the art.

Multidimensional oligomers of the formula: ##STR69## can also besynthesized with an Ullmann aromatic ether synthesis followed by aFriedel-Crafts reaction, as will be further explained.

Here, Q= ##STR70## q=--SO₂ --, --CO--, --S--, or --CF₃)₂ C--, andpreferably --SO₂ --, or --CO--; and

A₂ =a crosslinking end cap as previously defined.

To form the Ar--[--O--φ--CO--A₂ ]_(w) oligomers, preferably ahalo-substituted hub is reacted with phenol in DMAC with a base (NaOH)over a Cu Ullmann catalyst to produce an ether "star" with activehydrogens para- to the ether linkages. End caps terminated with acidhalide functionalities can react with these active aryl groups in aFriedel-Crafts reaction to yield the desired product. For example, 1mole of trichlorobenzene can be reacted with about 3 moles of phenol inthe Uhlman ether reaction to yield an intermediate of the generalformula:

    φ--[--O--φ].sub.3

This intermediate can, then, be reacted with about 3 moles of ##STR71##to produce the final, crosslinkable, ether/carbonyl oligomer.

The end caps crosslink at different temperatures (i.e. they apparentlydecompose in a reverse Diels-Alder at different curing temperatures), sothe cap should be selected to provide cured composites of the desiredthermal stability. That is, the backbone of the oligomer should bestable to at least the cure temperature of the caps. Themultidimensional morphology allows the oligomers to be cured at atemperature far below the use temperature of the resulting composite, socompletely aromatic backbones connected by heteroatoms are preferred toenhance the thermal stability.

Blends can improve impact resistance of pure oligomer composites withoutcausing a significant loss of solvent resistance. The advanced composite(i.e. mixed chemical) blends of the present invention comprise mixturesof one or more crosslinkable oligomer and one or more polymer from adifferent chemical family. The polymers are incapable of crosslinking.The crosslinkable oligomer and the compatible polymer can be blendedtogether by mixing mutually soluble solutions of each. While the blendis often equimolar in the oligomer and polymer, the ratio of theoligomer and polymer can be adjusted to achieve the desired physicalproperties. The properties of the composite formed from the advancedcomposite blend can be adjusted by altering the ratio of formula weightsfor the polymer and oligomer.

In synthesizing the polymers, quenching compounds can be employed, ifdesired, to regulate the polymerization of the comparable polymer, sothat, especially for linear systems, the polymer has an average formulaweight initially substantially greater than the crosslinkable oligomer.For thermal stability, an aromatic quenching compound, such as aniline,phenol, or benzoic acid chloride is preferred. The noncrosslinkingpolymer can be made by the same synthetic method as the oligomer withthe substitution of a quenching cap for the crosslinking end cap.

While the best advanced composite blends are probably those of modestformula weight and those in which the oligomer and polymer are inequimolar proportions, other compositions may be prepared, as will berecognized by those of ordinary skill in the art.

Solvent resistance of the cured composite may decrease markedly if thepolymer is provided in large excess to the oligomer in the blend.

The advanced composite blends may, in the case of the coreactive blendsor in other cases, include multiple oligomers or multiple polymers, suchas a mixture of an amideimide oligomer, an amide oligomer, and an imidepolymer or a mixture of an amideimide oligomer, an amideimide polymer,and an imide polymer (i.e. blended amideimide further blended withimide). When polyimide oligomers are used, the advanced composite blendcan include a coreactant, such as p-phenylenediamine, benzidine, or4,4'-methylenedianiline. Ethersulfone oligomers can include these imidecoreactants or anhydride or anhydride-derivative coreactants, asdescribed in U.S. Pat. Nos. 4,476,184 or 4,414,269. Other combinationsof oligomers, polymers, and coreactants will be recognized by those ofordinary skill in the art.

As discussed above, the oligomeric component of the advanced compositeblend may itself be a blend of the oligomer and a compatible polymerfrom the same chemical family, further blended with the compatiblepolymer from the different family. The advanced composite blends, also,can simply be made from three or more oligomeric or polymericcomponents. They generally include only one oligomeric component unlesscoreactive oligomers are used.

Curing may yield semi-interpenetrating networks of the general typedescribed by Egli et al., "Semi-Interpenetrating Networks of LARC-TPI"available from NASA-Langley Research Center.

The coreactive oligomer blends are prepared by mixing mutually solublemixtures of the two resins, in a method analogous to makingoligomer-polymer blends.

As suggested at the outset of the discussion of multidimensionalmorphology, formula weight matching in the cured composite poses aproblem. We have found it difficult to process high average formulaweight multidimensional oligomers, so we suspect that it will bedifficult to prepare an advanced composite blend that includes a polymerof relatively high average formula weight. To overcome this potentialproblem, we theorize that it may be possible to prepare a blend thatincludes the oligomer and polymeric precursors. For example, a polyetheroligomer of the general formula: ##STR72## might be mixed with polyamidepolymeric precursors of the general formulae: ##STR73## wherein Ar=anaromatic hub, φ=phenyl, and Q=a residue of a dicarboxylic acid, so that,upon curing, the oligomer crosslinks and the polymeric precursorscondense through the amine and acid to form a polyamide polymer. Thisapproach may be best suited for the lower curing oligomers. The productmay include addition polymers and block copolymers of the oligomer andone or both of the polymeric precursors.

Generally the coreactive oligomer blends are selected to tailor thephysical properties of the resulting block copolymer composites. Forexample, stiffening can be achieved for a composite made from anethersulfone oligomer by adding a benzoxazole oligomer as a coreactant.Those skilled in the art will recognize the benefits to be gainedthrough coreactive oligomer blends. The relatively stiff and rigidheterocycle oligomers can be toughened in this way.

Dopants for creating semiconductive or conductive composites with"Schiff base" oligomers are preferably selected from compounds commonlyused to dope other polymers, namely, (1) dispersions of alkali metals(for high activity) or (2) strong chemical oxidizers, particularlyalkali perchlorates (for lower activity). Arsenic compounds andelemental halogens, while active dopants, are too dangerous for generalusage, and are not recommended.

The dopants react with the oligomers or polymers to form charge transfercomplexes. N-type semiconductors result from doping with alkali metaldispersions. P-type semiconductors result from doping with elementaliodine or perchlorates. Dopant should be added to the oligomer or blendprior to forming the prepreg.

While research into conductive or semiconductive polymers has beenactive, the resulting compounds (mainly polyacetylenes, polyphenylenes,and polyvinylacetylenes) are unsatisfactory for aerospace applicationsbecause the polymers are:

(a) unstable in air;

(b) unstable at high temperatures;

(c) brittle after doping;

(d) toxic because of the dopants; or

(e) intractable.

These problems are overcome or significantly reduced with the conductiveoligomers of the present invention.

As used in describing the suitable diacid halides and diamines, "Schiffbase" is used throughout this specification in a generic way rather thanin its typical chemical way, and is used to represent conductivelinkages, such as --CH═N--, oxazoles, thiazoles, imidazoles, or mixturesthereof. The heterocycle oligomers may simply need to be doped toexhibit semiconductive properties, and --CH═N-- bonds may beunnecessary.

While conventional theory holds that semiconductive polymers should have(1) low ionization potentials, (2) long conjugation lengths, and (3)planar backbones, there is an inherent trade-off between conductivityand toughness or processibility, if these constraints are followed. Toovercome the processing and toughness shortcomings common with Schiffbase, oxazole, imidazole, or thiazole polymers, the oligomers of thepresent invention, include "sulfone" (i.e., electronegative) linkagesinterspersed along the backbone providing a mechanical swivel for therigid, conductive segments of the arms. Phenoxyphenylsulfone orphenoxyphenyl ketone moieties are preferred to provide added toughness.

The oligomers and blends of the present invention can be combined withreinforcing materials and cured to composite materials using heat orchemicals to activate crosslinking or interlinking between end caps.Prepregs can be prepared by conventional prepregging techniques. Whilewoven fabrics are the typical reinforcement, the fibers can becontinuous or discontinuous (in chopped or whisker form) and may beceramic, organic, carbon (graphite), or glass, as suited for the desiredapplication. Curing generally is conducted in conventional vacuumbagging techniques at elevated temperatures. The curing temperaturevaries with the choice of end cap. If desired, mixtures of end capsmight be used.

HYPOTHETICAL EXAMPLES 1. Synthesis of Compound (a) ##STR74##

A diamine of the formula H₂ N--R₃ --NH₃ is reacted with two moles of anacid anhydride of the formula: ##STR75## to form a dicarboxylic acidintermediate of the formula: ##STR76## The intermediate is converted tothe corresponding diacid chloride in the presence of SOCl₂, which isthen condensed with one mole of a diamine of the formula H₂ N--R₄ --NH₂and two moles of an amine end cap of the formula Y_(i) --φ--NH₂ to yieldthe desired product.

If excess diamine of the formula H₂ N--R₄ --NH₂ is used along with anacid halide end cap of the formula Y_(i) --φ--COX, the product can havethe formula: ##STR77##

2. Synthesis of compound (b) ##STR78##

A diamine of the formula H₂ N--R₃ --NH₂ is reacted with ##STR79## toyield a dianhydride intermediate of the formula: ##STR80## Theintermediate is then condensed with Y_(i) --φ--NH₂ and a diamine of theformula H₂ N--R₄ --NH₂ to yield the desired product.

3. Synthesis of compound (d) ##STR81##

A diamine of the formula H₂ N--R₃ --NH₂ is reacted with an acidanhydride as in Example 1 to form a dicarboxylic acid intermediate thatcan be reacted with another diamine of the formula H₂ N--R₄ --NH₂ and anacid halide end cap of the formula Y_(i) --φ--COCl to yield the desiredproduct.

4. Synthesis of compound (e) ##STR82##

An aromatic hub like triaminobenzene is condensed with a phthalyl acidanhydride and an amine end cap to yield the desired product.

5. Synthesis of compound (f) ##STR83##

An amine-substituted hub like triaminobenzene, is reacted with thedicarboxylic acid intermediate of Example 1, a diamine of the formula H₂N--R₄ --NH₂, and an amine end cap in the ratio of 1 mole ofhub:(w)(m+1)moles of intermediate:(w)(m) moles of diamine:w moles of endcap to prepare the desired multidimensional product.

6. Synthesis of compound (g) ##STR84##

An aromatic amine hub is reacted with the dianhydride intermediate ofExample 2, a diamine of the formula H₂ N--R₄ --NH₂, and an amine end capon the ratio of 1 mole hub:(w)(m+1) moles dianhydride:(w)(m) molesdiamine:w moles end cap to yield the desired product.

7. Synthesis of compound (h) ##STR85##

An aromatic acid or acid halide hub, like cyuranic acid, is reacted witha diamine of the formula H₂ N--R₄ --NH₂, a dicarboxylic acidintermediate of Example 1, and an acid halide end cap in the ratio of 1mole hub: (w) (m+1) moles diamine: (w) (m) moles intermediate: w molesend cap to yield the desired product.

8. Synthesis of compound (i) ##STR86##

An aromatic amine hub is reacted with a dicarboxylic acid intermediate(or dihalide) of Example 1 and an amine end cap on the ratio of 1 molehub: w moles intermediate: w moles cap to yield the desired product.

9. Synthesis of compound (j) ##STR87##

An aromatic amine hub is reacted with the intermediate of Example 8, adiamine, and an acid halide end cap in the ratio of 1 mole hub: w molesintermediate: w moles diamine, and w moles cap to form the desiredproduct.

10. Synthesis of compound (k) ##STR88##

An aromatic amine hub is reacted with the intermediate of Example 1, adiamine of the formula H₂ N--R₄ --NH₂, and an acid or acid halide endcap of the formula: ##STR89## on the ratio of 1 mole hub: (w) (m) molesintermediate: (w) (m) moles diamine: w moles end cap to form the desiredproduct.

The end cap is prepared by condensing an amine end cap of the formula:Y_(i) --φ--NH₂ with an acid anhydride of the formula: ##STR90## The acidhalide is prepared from the acid in the presence of SOCl₂.

11. Synthesis of compound (l) ##STR91##

An aromatic amine hub is reacted with the dicarboxylic acid intermediateof Example 1, a diamine of the formula: H₂ N--R₃ --NH₄, and an amine endcap in the ratio of 1 mole hub: (w) (m+1) moles intermediate: (w) (m)moles diamine: w moles end cap to form the desired product.

12. Synthesis of compound (m) ##STR92##

An aromatic amine hub is reacted with an acid halide anhydride of theformula: ##STR93## a diamine, and an acid halide end cap in the ratio of1 mole hub: w moles acid halide anhydride: w moles diamine: w moles endcap to form the desired product. Preferably the reaction occurs in twosteps with the reaction of the hub and acid halide anhydride followed bythe addition of the diamine and end cap.

13. Synthesis of compound (n) ##STR94##

An aromatic amine hub is reacted with an acid anhydride of the formula:##STR95## and an amine end cap on the ratio of 1 mole hub: w moles acidanhydride: w moles end cap to form the desired product.

14. Synthesis of compound (o) ##STR96##

An aromatic amine hub is reacted with the acid anhydride of Example 13,a diamine of the formula H₂ N--R₃ --NH₂, and an acid halide end cap inthe ratio of 1 mole hub: w moles acid anhydride: w moles diamine: wmoles end cap to yield the desired product. Preferably the reactionoccurs in two steps comprising the initial reaction between the hub andthe acid anhydride with the subsequent simultaneous addition of thediamine and end cap.

15. Synthesis of compound (p) ##STR97##

An aromatic amine hub is reacted with an acid anhydride of Example 13, adiamine of the formula H₂ N--R₃ --NH₂, and an amine end cap in the ratioof 1 mole hub: 2w moles acid anhydride: w moles diamine: w moles end capto yield the desired product. Preferably the end cap and half of theacid anhydride are mixed to form an end cap conjugate of the formula:##STR98## prior to mixing the reactants to form the oligomer. It alsomay be wise to mix the remaining acid anhydride with the hub to form anintermediate of the formula. ##STR99## prior to adding the diamine andend cap conjugate.

Alternatively, the product can be made by reacting the hub withdianhydride intermediate of Example 2 and an amine end cap.

16. Synthesis of compound (q) ##STR100##

An aromatic amine hub is reacted with the intermediate of Example 2, adiamine of the formula: H₂ N--R₄ --NH₂, and an end cap conjugate formedby reacting an end cap amine with an acid halide anhydride of theformula: ##STR101## in the ratio of 1 mole hub: w moles intermediate: wmoles end cap conjugate. The conjugate has the formula: ##STR102##

Alternatively, the product can be prepared by reacting the hub with anacid anhydride of the formula: ##STR103## followed by reaction with anamine of the formula H₂ N--R₃ --NH₂, the intermediate of Example 1, andan amine end cap. Stepwise addition of the diamine to the extended hubfollowed by addition of the intermediate of Example 1 and amine end capwill reduce competitive side reactions.

17. Synthesis of compound (r) ##STR104##

An aromatic amine hub is reacted with an acid anhydride of the formula:##STR105## to form an acid hub intermediate which is reacted with adiamine of the formula H₂ N--R₃ --NH₂, a dicarboxylic acid or acidhalide intermediate of Example 1, and an acid or acid halide end cap inthe ratio of 1 mole hub intermediate: (w) (m+1) moles diamine: (w) (m)moles dicarboxylic acid intermediate: w moles end cap to yield thedesired product.

Alternatively, the product can be formed by reacting an amine hub withthe dianhydride intermediate of Example 2, a diamine of the formula H₂N--R₃ --NH₂, and acid anhydride of the formula: ##STR106## a seconddiamine of the formula H₂ N--R₃ --NH₂, and an acid halide end cap in astepwise reaction.

18. Synthesis of compound (s) ##STR107##

An aromatic amine hub is reacted with the dianhydride intermediate ofExample 2, a diamine of the formula H₂ N--R₃ --NH₂, and an amine end capin the ratio of 1 mole hub: 2 w moles intermediate: w moles diamine: wmoles end cap to yield the desired product.

19. Synthesis of compound (t) ##STR108##

An aromatic acid hub is reacted with a diamine, an acid anhydride, andan amine end cap in the ratio of 1 mole hub: w moles diamine: w molesacid anhydride: w moles end cap to yield the desired product. Preferablythe reaction includes the steps of reacting the acid anhydride with theend cap prior to addition of the hub and diamine.

20. Synthesis of compound (u) ##STR109##

An aromatic acid hub is reacted with a diamine to form an amine extendedhub conjugate that is reacted with an acid halide anhydride, anotherdiamine, and an acid halide end cap to yield the desired product.Preparing an end cap conjugate by reacting the second diamine with theend cap prior to the addition of the other reactants reduces side orcompetitive reactions.

21. Synthesis of compound (v) ##STR110##

An aromatic acid hub is reacted with a daimine, the intermediate ofExample 1, and an amine end cap in the ratio of 1 mole hub: w molesdiamine: w moles intermediate: w moles end cap. Preferably, the reactionoccurs in two stages with the hub being mixed with the diamine to forman amine conjugate to which the acid or acid halide intermediate and endcap is added simultaenously.

Comparable oligomers to those described in Examples 1-21 can be preparedby using the same diamine H₂ N--R₃ --NH₂ in the condensation reaction toprepare the intermediate acids or anhydrides and in the oligomericcondensation. That is, in these oligomers, R₃ is the same as R₄.

22. Synthesis of a multidimensional polyamide

The oligomer is prepared by reacting: ##STR111## under an inertatmosphere to yield: ##STR112##

23. Synthesis of another polyamide

Another preferred multidimensional oligomer is prepared by reacting:##STR113## under an inert atmosphere to yield: ##STR114## whereinq=--SO₂ --, --CO--, --S--, or --(CF₃)₂ C--, and preferably --SO₂ -- or--CO--

24. Synthesis of a difunctional, multidimensional polyamide

The oligomer is prepared by reacting: ##STR115## under an inertatmosphere to yield: ##STR116##

Competitive side reactions will likely hinder the yield of this productand will make isolation of the product difficult. Yield can be enhancedby adding the reactants serially, but the physical properties of theresulting oligomers might be impaired.

In Examples 22-24, the end cap monomer might be A₂ --NH₂.

25. Synthesis using an etheramine hub

Yet another multidimensional oligomer is prepared by reacting:##STR117## under an inert atmosphere to yield: ##STR118##

26. Synthesis of a multidimensional polyamide using anhydride end cap

The oligomer is prepared by reacting: ##STR119## under an inertatmosphere to yield: ##STR120##

In Examples 25 and 26, the end cap monomer might be ##STR121##

27. Synthesis using melamine as a hub

The oligomer is prepared by reacting melamine with nadic anhydride toyield: ##STR122##

28. Synthesis of a polyamide having an acid halide hub, a diamine arms,and anhydride end caps

The oligomer is prepared by reacting about 1 mole of ##STR123## withabout 3 moles of phenylenediamine and about 3 moles of ##STR124## toyield primarily: ##STR125##

Better yield might be obtained by reacting the anhydride withaminobenzoic acid and converting the --COOH functionality to an aminefollowed by condensation of the monofunctional amine cap with the acidhalide hub.

29. Preparation of an advanced composite blend

The polyamideimide oligomer of Example 1, wherein R₂ =R₃ =R₄ =phenyl,m=1, i=2, and Y= ##STR126## is dissolved in a suitable solvent.

A relative high average formula weight polyether polymer is made bycondensing a dialcohol of the general formula:

    HO--φ--O--φ--O--φ--O--φ--OH

with Cl--φ--Cl and phenol (to quench the polymerization) under an inertatmosphere in the same solvent as used with the polyamideimide oranother solvent miscible with that of the polyamideimide.

The two solutions are mixed to form the advanced composite blend, whichcan be prepregged or dried prior to curing to an advancedamideimide/ether composite.

30. Preparation of a multidimensional advanced composite blend

A multidimensional, polyether sulfone oligomer is prepared by reactingphloroglucinol with Cl--φ--Cl and a dialcohol of the general formula:HO--φ--O--φ--SO₂ --φ--O--φ--OH. The polymerization is quenched with apyrimidine-based end cap monomer. The condensation occurs in a suitablesolvent under an inert atmosphere. The product is not recovered from thesolvent.

A multidimensional, polyamide polymer is prepared in the same solvent asused for the oligomer or in another miscible solvent by condensingcyuranic acid chloride with aniline. The product is not recovered, butthe reaction mixture is mixed with the polymer product to form amultidimensional advanced composite blend that can be prepregged ordried prior to curing to form a multidimensional,polyamide/polyethersulfone composite.

The oligomers or blends can also be used as varnishes, films, adhesives,and coatings.

While para isomerization is shown, other isomers are possible.Furthermore, the aryl groups can have substituents, if desired, such ashalogen, lower alkyl up to about 4 carbon atoms, lower alkoxy up toabout 4 carbon atoms, or aryl. Substituents may create steric hindranceproblems in synthesizing the oligomers or in crosslinking the oligomersinto the final composites.

While preferred embodiments have been described, those skilled in theart will readily recognize alterations, variations, or modificationswhich might be made to the embodiments without departing from theinventive concept. Therefore, the claims should be interpreted liberallywith the support of the full range of equivalents known to those ofordinary skill based upon this description. The claims should be limitedonly as is necessary in view of the pertinent prior art.

We claim:
 1. A compound of the general formula ##STR127## wherein R₁=lower alkyl, lower alkoxy, aryl, aryloxy, substituted alkyl,substituted aryl, halogen, or mixtures thereof;j=0, 1, or 2; G=--CH₂ --,--O--, --S--, --SO--, --CO--, --CHR--, --CR₂ --, or --SO₂ --;T=methallyl or allyl; Me=methyl; R=hydrogen, lower alkyl, or phenyl;Ph=phenyl; ##STR128## Q=--NH₂, --COX, --NO₂, or --COOH; and X=halogen.2. The compound of claim 1 wherein Q is --NH₂.
 3. The compound of claim1 wherein Q is --COX.
 4. The compound of claim 1 wherein Q is --COOH. 5.The compound of claim 1 wherein Q is --NO₂.
 6. The compound of claim 1wherein Q is --NH₂ and Y is ##STR129##
 7. The compound of claim 1wherein Q is --COX and Y is ##STR130##
 8. The compound of claim 1wherein Q is --COOH and Y is ##STR131##
 9. The compound of claim 1wherein Q is --NO₂ and Y is ##STR132##
 10. A compound of the generalformula ##STR133## wherein Y= ##STR134## wherein R₁ =lower alkyl, loweralkoxy, aryl, aryloxy, substituted alkyl, substituted aryl, halogen, ormixtures thereof;j=0, 1, or 2; G=--CH₂ --, --O--, --S--, --SO--, --CO--,--CHR--, --CR₂ --, or --SO₂ --; T=methallyl or allyl; Me=methyl;R=hydrogen, lower alkyl, or phenyl; Ph=phenyl; ##STR135## Q=--NH₂,--COX, --NO₂, or --COOH; and X=halogen.